Door holding device



Dec. 12, 1961 G. BARTr-:L 3,012,269

DOOR HOLDING DEVICE Filed Sept. 3, 1958 7 f --TAQ-J--iaL-#F- lf/ .9 L/2 Wa Pig.

INVENTOR.

G UNTER EAR Tf1.

United States Patent O 3,012,269 DOOR HOLDING DEVICE Gnter Bartel, Osnabrueck, Germany, assignor, by mesne assignments, to Mobay Chemical Company, Pittsburgh,

Pa., a corporation of Delaware Filed Sept. 3, 1958, Ser. No. 758,728 Ciaims priority, application Germany Sept. 6, 1957 8 Claims. (Cl. 16-86) This invention relates generally to a door holding device and, more particularly, to an improved resilient door holding device for motor vehicles which arrests the movement of the door in certain open positions.

It has been proposed heretofore to provide door holding devices for vehicle doors. When the door is opened, it is held in the open position by the door holding device to prevent closing of the door as persons are entering or leaving the vehicle. The heretofore known door holding devices usually comprise either, a metallic member hinged to a door post which extends into a door through an opening and has near its opposite end a notch which frictionally engages the opening when the door is opened, or a spring-like metallic plate member which acts on a door hinge arm throughout its arc of travel. The plate member has a depression in which the hinge arm will seat in the open position of the door. These arrangements enable the door to be held in an open position even though the vehicle is in such a position that ordinarily the door would swing closed due to the force of gravity. These heretofore known door holding devices, however, have several distinct disadvantages. For example, it is often difficult to move the door from a stop position because of frictional resistance. Moreoventhe metallic elements are noisy in their operation; and, usually, the parts, become so worn as to eventually destroy their function.

It is, therefore, an object of the present invention to provide a flexible door holding device which assures positive arrest of an automobile door in one or more stop positions. It is another object of the present invention to provide a door holding deviceV which allows the door to move into and out of stop positions easily and without undue resistance due to friction. Still another object of the present invention is to provide a door holding device which in operation is substantially without noise. A further object of the present invention is to provide a door holding devicewhich substantially eliminates frictional wear. Still another object of the present invention is to provide a resilient door holding device which is made of an abrasion-resistant plastic. A still further specific object of the present invention is to,v provide a resilient door holding device which is manufactured from a homogeneous nonporous rubber-like polyurethane which can be made in a simple economical manner.` i

Other objects will become apparent with the following detailed description of the invention and with reference to the accompanying drawing in which:

FIGURE l is a vertical partial cross-section view illustrating a preferred embodiment of the present invention;

FEGURE 2 is a sectional view taken in the direction of the arrows 2--2 of FIGURE l; and

FIGURE 3 is a sectional view taken in the direction of the arrows 3 3 in FIGURE 1.

The above objects and others are accomplished in accordance with the'present invention, generally speaking, by providing a door holding device Vcomprising essentially two parts, a moveable resilient rod hinged to a door post which extends into a door and within a guide arrangement aixed 'within the door. The unfastened end of the resilient rod moves with the door in an arc as the door is 3,012,269 Patented Dec. 12, 1961 ICC stop positions by the inter-action of the resilient rod with the guide arrangement. The relative movement of the resilient rod within the guide arrangement is accomplished 4through the elastic displacement of the resilient material. It is pointed out that not only the rod may be made of resilient material, but also the guide arrangement may have a covering of resilient material. Once a stop position. has been reached, it is securely maintained thereat until a force intended to move the door overloads the elastic energy and forces a relative movement out of this position under a renewed elastic displacement of resilient material.

It has been found useful to provide the resilient rod with tapers which begin to increase as the stop positions are approached by the guide arrangement when the door is being opened. The tapers are essentially increased in cross-section of the resilient rod in a direction away from the hinge point and towards the respective stops on the rod. In a preferred embodiment, the resilient rod is constructed with a reinforcing bar of spring steel or the like embedded therein. A The stops, as well as the tapers leading to them, are preferably formed of a tlexible rubberlike polyurethane. The shaped flexible resilient rod provided by this invention may be cast from any suitable substantially nonporous rubber-like polyurethane plastic in which may be provided any desired cast-in place reinforcing element.

Any suitable substantially nonporous rubber-like polyurethane may be used to cast the flexible resilient door holding device provided by this invention, but best results are obtained when the polyurethane has a Shore A hardness of from about 70 to about 90, an elasticity of from about 30% to about 50%, and an elongation of from about 300% to about 600%. For example, the polyurethane may be prepared by reacting any suitable organic polyisocyanate with any suitable organic compound having reactive hydrogeus and capable of reacting with the polyisocyanate to form a polyurethane. For

example, 1,5-naphthylene diisocyanate, p-phenylene diisocyanate, or 4,4'-diphenyl dimethylmethane diisocyanate may be reacted with a polyester, polyalkylene ether glycol, a polythioether glycol or the like having terminal groups which are predominately hydroxyl groups and a molecular weight of at least 750 and the resulting product may be cross-linked with an organic chain extender or crosslinken Suitable cross-linking agents include ethylene y glycol, diethylene glycol, butanediol, diprimary aliphatic opened and arrests the movement of the door incertain and aromatic diamines, such as, toluylene diamine, or the like. Indeed, any organic compound having reactive hydrogen atoms may be reacted'with an organic polyisocyanate, and a cross-linker as disclosed Vin U.S. Patents 2,729,618; 2,621,166; and 2,620,516 to form the polyurethane and any of the processes disclosed in these patents may be followed in making a polyurethane suitable for the present invention. Usually they door holding device will be formed by pouring a molten polyurethane .in a suitable mold and about any metal parts to be `embedded therein, and the contents o-f the mold. will then be heated until cross-linking and curing has been obtained with solidication of the polyurethane into a flexible rubber-like substantially nonporous product having the shape of the mold.V

It has been found that the door holding device provided by the present invention is not'adversely affected by prolonged'exposure to weather orjsuch materialsV as oil and the like. vThe nonporous rubber-like polyurethane plastic is especially highly resistant to abrasion which guarantees along service life for the door holding device;

The flexibility of the polyurethane plastic maybe increased -through the addition, during t-he manufacturing,

process, of activators, such as, for example, an alkali metal salt of an vorganic fatty acid or an aryl sulphonate, alkyl 3 sulphonate, or aryl alkyl sulphonate, respectively. EX- amples of alkali metal salts of organic fatty acids are sodium oleate, potassium oleate, sodium stearate, potassium stearate, lithium linoleate, and the like. Examples of suitable sulphonates include dioctyl sodium sulphonate and isopropyl naphthaline sodium sulphonate. An important advantage of Ithe nonporous rubber-like polyurethane as a material consists in the fact that in the molten stage it can be cast or molded into any desired form.

The frictional characteristics, i.e. the coeiiicient of fricv tion, of the polyurethane plastic may be improved by the addition to the polyurethane melt of lubricating agents, such as, silicone oil, hydrocarbons, and molybdenum disulfide. Each of these lubricating agents may be added in quantities of from about 0.01% to about 5% by weight, and preferably from about 0.1% to about 1% by weight, based on the weight of the cured rubber-like polyurethane plastic.

Any suitable hydrocarbon may be utilized as a lubricant, such as, for example, high boiling petroleum fractions including kerosene and conventional'lubricating oils and waxes including paraffin, beeswax, ceresin, and the like.

The molybdenum disulfide should preferably be ofY a high technical grade and of high purity. Methods for preparing substantial pure molybdenum disulfide are disclosed in U.S.VPatents 2,367,946 and 2,686,156. The products of the methods disclosed in these patents are particularly well suited for use in this invention.

Any suitable liquid organo-polysiloxane may be used as the silicone oil, provided the viscosity thereof is from about 5=0`to about 500 centistokes at 20 C. Examples of suitable silicone oils include dimethylsiloxane polymers 'having a viscosity of about 50 centistokes at 20 C., di-

' ample, thecoeificient of friction between the rubber-like polyurethanes and steel is about 0.1.

Referring again to the drawing for a more detailed descriptionof the invention; FIGURE 1 illustrates in a partial section a door 4 hinged to a door post 1. The

' door post is provided with a pin 2 which anchors one end of the resilient rod to the door post. The resilient rod comprises a reinforcing metallic element 7 about-which has been cast a substantially nonporous rubber-like polyurethane Shaving a Shore A hardness of from about `70 to about 95, an elasticity of from about 30% to about Y 50%, and anrelongation of from about 300% to about 600%. .A slot 3 is provided in door 4 so that the resilient rod will not interfere with the movement of the door 4. Axed' to the interior of door 4 is a guide arrangement comprising twooffset rollers 5 which haveia covering 6 of a nonporous rubber-like polyurethane having a Shore A hardness of from about 70 to about 95; an elasticity of from about 30% to about 50%, and an elongation of fromVY With theV opening 'of the section or taper 12 is provided towards the stop position 10. FIGURE 2 illustrates the elastic displacementA between the resilient rubber-like polyurethane 8 of the rod and the covering 6 ofthe rollers 5 of the guide arrangement. FIGURE 3 is a side elevation view of ther-.door

l"holding device in whichthe guide arrangement and the door 4 are taken in section.

v t percent to about 600 percent, said rod adapted-to be The following example illustrates the preparation of one polyurethane suitable for forming the door holding device provided by this invention:

Example l 1,000 parts by weight of an hydroxyl polyester obtained by thermal esterii'ication of about l1 mols of adipic acid with about 12 mols of ethylene glycol and having an hydroxyl number of about 52 and an-acid number of about 1 are heated to a temperature of about 135 C. and under a vacuum of about 12 mm. until the formation of bubbles has stopped and the polyester-is completely free from water. Now, 180 parts by weight of naphthylene-1,5di

isocyanate are added at 135 C. to the dehydrated polyester while stirring. As soon as the temperature starts to drop, 20 parts by Weight of butylene glycol-1,4 are stirred into the mixture at about 135 C. The resulting mixture is poured into a suitable mold. This has been so designed that any rigid element may be inserted in the mold in properly alined relation and the polyurethane is cast thereabout and solidified by curing. The above mixture is maintained in the mold at a temperature of about 110 C. for about 24 hours 4to form a'homogeneous polyurethane rubber. After 24 hours the resilient rod is removed from the heating chamberV and the material then shows the following properties: Shore A hardness 90, resiliency 35%, elongation 450%.

It is to be understood that any suitable organic polyisocyanate, organic compound having reactive hydrogen atoms, and cross-linking agent may be substituted for those in the foregoing example. Examples of these maten'als suitable for this purpose are found in the aforesaid patents. Moreover, it is to be understood that variations are permissible in the temperatures and processing steps as long as lthe product obtained has the required physical characteristics. f

As indicated hereinbefo're,V` the molecular weight of the organic compound having Vreactive hydrogen atoms which is reacted with theV organic polyisocyanate in the preparation of the polyurethane should be at least about 750. Although the chemistry involved in the preparation of thepolyurethane is not speciiically involved in this invention because any polyurethane having the required physical characteristicsmay be used to form the door holding device, it is considered advisable'to point out that the polyester may be prepared by esteriication of any suitable polycarboxylic acid, such as, for example, adipic acid, succinic acid, and the like. A desirable polyalkylene ether glycol may be prepared by the condensation of a lower alkylene oxide, such as, for

example, ethylene oxide, propylene oxide, butylene oxide, and the like. Y Y

Although the invention has been described in considerable detail in the foregoing for the purpose' of illustration, it Visgito be understood that such detail is solely for this purpose and that variations can be made by those'slgilled in the ait without departing from'the spirit and scope-of Vthe inventionexcept as is Set forth in the claims.

What is claimed 'isz' 1. A door holding device for motor vehicles comprising a tapered solid resilient rod vof a nonporous polyurethane plastic having a Shore A hardness of from about to about 95, ari-elasticity of from about 30 percent to about 50 percent andan elongationof from about 300 hinged'to a door post and Vhavinga free Yend adapted to extend into a door hinged on said .door post, a pair of spaced-apart rollers' adapted to the aixed in the door,

means provided in said rod and operating in conjuncnon withrsaid rollersV forarrestingthe ymovement of said door comprising at least one area of constriction onrs'aid resilient rod intowhich saidrollers move by'compressing said resilient rodl adjacent said constriction.

2. A Vdoor holdingdevicezcomprising Ya pair ofspaced plastic having a Shore A hardness or" from about 70 to about 95, an elasticity of from about 30% to about 50%, and an elongation of from about 300% to about 600%.

4. A door holding device comprising a pair of spaced apart rollers atxed a door adjacent a slot provided in said door, a solid tapered resilient rod pivotally connected -to a door post and extending into said door through said slot and between said rollers, the distance between :said rollers being less than the smallest width between the edges of said rod engaged by said rollers, said rod having an increasing width in a direction away from said pivot connection and at least one depression therein for engagement with said rollers for arresting the movement of said door 'in the open position.

5. The door holding device of claim 4 wherein said resilient rod comprises a non-porous polyurethane plastic having a Shore A hardness of from about 70 to about 95, an elasticity of from about 30% to about 50%, and an elongation of from about 300% to aboutV 600%.

6. A door holding device comprising a pair of spaced apart rollers aihxed within a door adjacent a slot provided insaid door, a solid tapered resilient rod pivotally connected to adoor -post and extending into said door through said slot and between said rollers, said resilient rod comprising a non-porous polyurethane plastic portion having a Shore A hardness of from about 70 to about 95, an elasticity of from about 30% to about 50%, and an elongation of from about 300% to about 600% and a metallic reinforcing member substantially embedded in said polyurethaneV plastic, the distance be? tween said rollers being less than the smallest width between the edges of said rod engaged by said rollers, said rod having an increasing width in a direction away from said pivot connection and at least one depression therein for engagement with said rollers for arresting the movement of said door in the open position.

7. A door'holding device comprising a pair of spaced apart rollers aixed within a door adjacent a slot provided in said door, a solid tapered resilient rod pivotally connected to adoor post and extending intosaid door through said slo-t and between lsaid rollers, said resilient rod comprising a non-porous polyurethane plastic portion having a Shore A hardness of from about 70 to about 95 an elasticity of from about 30% to about and an elongation of from about 300% to about 600% and a metallic reinforcing member substantially Vembedded in said polyurethane plastic, the distance between said rollers being less than the smallest width between the edges of said rod engaged by said rollers, said .rod having at least one depression therein for engagement with said rollers for arresting the movement of said door in the open position.

8. A door holding device for motor vehicles comprising a tapered'solid resilient rod adapted -to be hinged to a door post and having a free end adapted to end into a ydoor hinged on said door post, a pair of spaced apart rollers adapted to be aixed in the door, said resilient rod comprising a non-porous polyurethane plastic portion having a Shore A hardness of from about to about an elasticity of from about 30% to about 50%, and an elongation of from about 300% to about 600% and a metallic reinforcing member substantially embedded in said polyurethane plastic, means provided in said rod and operating in conjunction with said rollers for arresting the movement of said doorrcomprising at least one area of constriction on said resilient rod into which said rollers move by compressing said polyurethane plastic adjacent said constriction.

References Cited in the le of this patent UNITED STATES PATENTS UNITED STATES PATENT OEETCE CERTIFICATE OF CORRECTION Pat-ent No.- 3,012,269 December 12s, T961 It is hereby certified that error appearswnt'bhe above ifi'u'inber'cl pat-l' enb requiring correction and that the said Letters Patent should read es "corrected below.

Column 5l line l, for "with" within column IEEE 24, for "end" read extend Sgne Yand4 sealed this 15th day o- May I92 (SEAL) DAVID L. LADD Commissioner of Patents ERNEST W'SWIDER.. Attesting Officer I n N 

